I’m uploading videos using the YouTube Data API v3 via the videos.insert endpoint.

It's known that there's no explicit API parameter to make a video short. However, we expected videos that are <= 60 seconds to be posted as shorts. It now seems that longer videos can not be posted as short (<= 3 minutes).

Can we please get clarity around how YouTube determines whether a video becomes a short?

For example:

• What is the max duration requirement (e.g., 60s or 3 minutes)?

• Does the aspect ratio need to be vertical (e.g., 9:16)?

• Does resolution matter (e.g., 1080×1920)?

Thank you for the help!